On Monday, after days of teasing, Rihanna and Chris Brown debuted two songs featuring each other. Brown sings and raps on the remix of Rihanna's sexually charged song "Birthday Cake," and she appears on a new version of his upbeat tune "Turn up the Music."

Fans have been split about the topic: Some support Rihanna and Brown's collaborations, others condemn it. The topic was still trending on Twitter on late Tuesday, with plenty of tweets criticizing Rihanna for embracing her former abuser.

Rihanna seemed to address the controversy Tuesday when she won best international female artist at the Brit Awards.

"At times when I feel misunderstood, my fans always remind me that it's OK to be myself," Rihanna said.

But Bill Werde, editorial director of the music trade publication Billboard, says Rihanna's decision to make music with Brown could disappoint some of her supporters.

"I think there are people out there that feel betrayed (by) Rihanna," he said. "She has every right to be an individual ... she has every right to date who she wants to date and be with whoever she wants to be with. She's a grown woman. But you just need to recognize that then the fans have every right to feel how they're going to feel about that."

Emails to both Brown and Rihanna's record labels asking for more information on the songs went unreturned Tuesday, and while Rihanna's representative had no comment, Brown's publicist did not return a request for comment.

When rumors about the collaboration sparked last week, both stoked the talk about it. Brown tweeted: "Let them be mad!!!! We make music. Don't like it, don't listen!" On Tuesday, after weighing some of the negative feedback, he tweeted: "You are not GODS to judge us. U have no say! Positivity & LOVE! My fans make a difference."

The release of the songs comes three years after Brown attacked his then-girlfriend on the eve of the Grammys, leaving her with a split lip, a black eye and other injuries.

Later that year, when she addressed the assault in an interview with ABC, she went into detail about how Brown punched and bit her during an argument that turned violent. She said Brown had "no soul in his eyes" and she had no idea how the beating would end. She also warned other women facing domestic violence to not let themselves become blinded by love.

"I think the existence of these (songs) show that she's still kind of struggling with that, as many humans would," said Werde.

After Brown pleaded guilty to a felony charge, he saw his career plummet: A former Billboard artist of the year, he lost endorsements and his third album, "Graffiti," released 10 months after his attack, was a commercial disappointment. A restraining order prevented him from being close to Rihanna and he was put on probation (which remains in effect). Since then, he's returned to the top of the music charts, releasing a slew of hit songs and the album "F.A.M.E. (Forgiving All My Enemies)," which won him his first Grammy this month. He also made his physical return to the Grammys, the same night Rihanna performed (the restraining order is no longer in effect). Brown performed twice at the show, which drew criticism.

But now Rihanna may face criticism as well. Werde, who expects the songs to find success, says he doesn't believe she'll lose any of her endorsements, but adds that image could change.

"This will be white-hot for a few minutes in the big scheme of things and then it will die down. But what's going to be left behind is the complicated residue of who Rihanna is as a role model," he said.

Even before the songs were officially released, Billboard addressed the matter in open letters to Rihanna and Brown. In Rihanna's letter, Billboard said her pairing with Brown was "not cool, to a whole lot of people."